Pressure-fluid motor



E. H. sHAFF 1,781,133

PRESSURE FLUID MOTOR Filed Deo. 2, 1926 2 Sheets-Sheet l Nov. 11, 1930.

NOV. 11, 1930. E, H, SHAFF 1,781,133

PRES SURE FLUID MOTOR Filed Dec. 2, 1926 2 Sheets-Sheet 2 Patented Nov. 11, 1930 UNIT-ED STATES ,PifrEN'ry ori-lcs ERNEST H. SHAFF, OF GRAND HAVN, MICHIGAN, ASSIGNOR TO WILLIAM KELLER, INC., OF'GRAND HAVEN, MICHIGAN, A. CORPORATION' OF MICHIGAN PRESSURE-FLUID MOTOR Application led December 2, 1926.V Serial No. 152,107.

This invention pertains generally to pressure fluid motors and particularly relates to improvements in motors ofthe type described, illustrated and claimed in my copending application Serial No. 9,392, ling date February 16th, 1925.

In that 'application I have describedand illustrated a h and held motordevice in which a rotary tool is operated by a compressed air motor comprising a circumferentially arranged group of cylinders and pistons acting upon a crank plate providing a series of combined bell cranks which operate to impart a gyratory motion to a pin or arm moving in a conical path. The gyratory thepower impulses which are successively.

applied to the crank plate, with increased efiiciency.

Another object of the invention is to provide a more advantageous means for attaching the pistons to the gyratory plate to facilitate the assembly thereof.

Other objects and advantages will become apparent as the description of the invention proceeds and also from the accompanying drawings, in which:

- Figure 1 represents a longitudinal 'section of the device as a whole.

Fig. 2 is a vertical cross section of the valve member on the line 2--2 of Fig. 1.

Fig. 3 is a vertical cross section on the line 3--3 of Fig. 1, showing an end view of the cylinder block.

Figs. 4 and 5 are views take-n on the lines 4 4 and 5-5 of Fig. 1 showing the opposite sides of the gyratory plate.

Fig. 6 is a longitudinal fragmentary sec- 'able means, such as the bolts 20.

ysively, which power impulses are thereupon tion of the cylinder block 6-6 of Fig.f3.

Fig. 7 is an enlarged vertical section of he valve mechanism on the line 7-7 0f ig. 8 is an enlarged longitudinal section of the valve mechanism on the line 8--8 of Fior. 7.

Fig. 9 is a view similar to Fig. 7, but taken on the line 9 9 of Fig. 8.

Fig. 10 is an enlarged elevation of the rotary sleeve of the valve member.

For purposes of illustration I have herein shown my invention as embodied in a pneumatic rotary drill'. This drill comprises a casing having a handle section, a cylinder block, and a crank plate assembly housing. The handle section, designated generally as 11 is herein shown in the form of a pistol grip and includes a manually operable air control mechanism 12, and a valve housing 13. The. cylinder block 14 has therein a plurality of radially arranged cylinders 15, within each taken on the line -of which a piston 16 operates to actuate a' bell crank plate assembly 17 contained in the 75 housing 18 which is formed as a continuation of the cylinder block and has a drill spindle 19 journalled therein. These three sections are secured in working relation by any suit- Compressed air, under the control of a valve mechanism, to be presently described, is admitted at appropriate intervals to transmit power impulses to the pistons succes- S5 transmitted tothe wabbling bell crank plate or pressure member 17 and thence to a gyratory crank arm shaft 21. The-crank arm shaft through suitable connections22 at one end thereof drives a tool spindle 19 and at the other end is arranged to operate the air-controlling valve mechanism.

It has been found desirable, in devices of this type wherein a plurality of reciprocating parts move at high speed, to provide -means for deadening the shock of the parts when such parts reach the end of the return stroke. Such shock may be caused by the fact that during said'return stroke under ordinary conditions the parts are under no preswe sure or tension which might take up any slack, loosene'ss or play in the parts. This play causes them to .s1av to ether when air is admitted to that cylinder lmmediately after thel piston reaches the end of the exhaust stroke. The means by which I haveovercome this objectionable feature comprises an air exhaust under control off` the valve mechanism bylwhich the piston is required to exert a slight working pressure to exhaust the final amount of air in the cylinder, thus effectually cushioning the return stroke.

As disclosed'in the drawings with special reference to Figs. 1-7-8-9-10, the valve mechanism comprises a rotatable cylindrical sleeve 23 mounted in a bushing 24, which is firmly seated in a recess 25-providedvin the base of the handle 11. The recess 25 and the bushing 24.are positioned centrally of the base of the handle, which part abuts and is secured to the ycylinder block 14. Near the inner end of the recess an internal annular groove 26 is connected to an air supply duct 27 leading throu h the handle-11 from 'a suitable source o? supply. A plurality of circumferentially arranged ports 28, in number one for each cylinder, are positioned in the bushing to register with the annular groove 26 in the recess, anda second series of somewhat larger, preferably rectangular ports 29 are provided near the outer end of said bushing in axialalinement with the first mentioned ports 28. The second series of ports 29 communicate with a series of passageways 30 which lead toa point adja- Acent the center of each cylinder.

The sleeve 23 has a peripheral channel 31 (F ig.'9) provided thereon at an appropriate point, which channel during the rotation of the sleeve provides successive communication between each port 28 and its correspondingly alined port 29. Thus during the rotation of the sleeve 23 air will be admitted to each of the c lindersl in progressive sequence througii its corresponding port 28, t-he channel 31 in the sleeve 23, the second port 29 v and the passageway 30.

Iny this instance I have produced the cushioning7 effect through a specially designed exhaust vent in the cylindrical sleeve 23. The vent 32 as shown in Fig. 10, comprises an opening through the sleeve, diagonally disposed from the channel 31, said opening being relatively large at one side and throughout the major portion of its width,v

but diminishing rapidly to a narrow neck 33 at the other side. The interior of the sleeve 23 has free communication with the atmosphere through an opening 34 in the handle. It will be apparent that as the piston commences its y return or exhaust stroke, the air will be exhausted rapidly from the cylinder, during the initial portion of said stroke. However, as the piston nears the end of the exhaust stroke, the narrow neck of the vent moves into registry with the port, narrowing the sizeof the vent opening and building up av slight pressure in the cylinder.` This pressure, while diminishing, createsv a slight resista-nce which the piston must overcome. Consequently, the 4movable parts of the assembly are constantly under the influence of forces which tend to hold the` parts in the .same relative position-with' a resulting eliminat-ion of assembly.

In general, t-he operating mechanism is substantially similar to,that set forth in my aforementioned copending application. Thus, itcomprises a plurality of bell crank arms provided by the unitary crank plate designated generally as 17 (Fig. 1) and mounted for rotational movement relative to a gyratory crank arm 21. The crank .arm is preferably formed integral 'with a shaft 35 extending rearwardly through the cylindery block .14 and adapted to rotate ina sleeve 36 nonrotatably held therein. Also integra-l with the crank arm at its front end is`a second shaft 37 arranged, through the medium of gears 22, to drive the work spindle 1-9.l

In the vconstruction of the crank plate 17 I preferto employ a three part construction comprising an inner sleeve 38 secured to an intermediate gear ring 39 on which an outer play, slapping or knocking in the socket ring 40 is rigidly mounted. .The inner sleeve as shown herein is a tubular member fitting intothe intermediate ring 39 so las to project rearwardl therefrom. The rear end of this sleeve is o set to provide one ball race 41, and the sleeve is secured firmly to the intermediate gear ring 39 as by a driving fit.

`The intermediate ring 39 comprises a somewhat cylindrical ring providing at one end a ring gear .42 integral therewith. At the other end of the ring is formed a ball race 43 for a second ball bearing, which is in the nature of a thrust bearing. The outer socket ring is fitted over the intermediate ring preferably from the rear side of the latter, and the two parts are pressed or otherwise rigidly secured.

together. A pair of appropriate seats 44 provided oneon each of the inner and outer suri faces of the intermediate ring 39, are arranged to receive the sleeve 38 and the .outer ring 40. At appropriate intervals, depending upon they number df cylinders and pistons in the motor, the outer ring has formed therein a plurality of herispherical depressions` or sockets 45, and seated in each depression is a separate hemispherical cup 46 forming an intermediate socket adapted to receive a ball 47 on the end of a piston rod 48. Suitable means for so securing the parts together may comprise a bolt 49 rigid with and extending from the outer surface of the intermediate socket member or cup 46 through an appropriately positioned opening in the socket 45 .and secured in that relation by a nut 50 on the bolt. In this manner a ball and socket the mounting therefor,

(in v junction between the piston rod 48 and the wabbling crank plate 17 has been effected which may be readily and easily disassembled forpurposes of repair or replacement.

The piston rod balls 47 which fit into the v intermediate sockets, as Well 'as the balls 51 at the opposite ends of thepiston rods 48 are preferably hollow for the purpose 0f eliminating any unnecessary dead Weight whose inertia'must be overcome at each end of the stroke of the piston.

Asshown in Fig. 1, the crank plate, when assembled, has a central opening therethrough at one end of which is the all racc 43 on the intermediate ring 39 and at the other end the ball race 41 on the inner sleeve 38, At either end of the crank arm 21, which extends through the crank plate 17, an en larged section 52 is cupped to provide ball races 53 and 54 facing the ball races 43 and 41 on the intermediate ring 39 and on the sleeve 38.

As shown in Figs. 1 and 5, the crank arm 21 has alongitudinal bore 55 extending substantially throughout its length, and near the outer end of the bore is an opening 56 which registers with the ball races at that end. A plug 57 mounted on a resilient member such as the U-shaped spring 58 is arranged to be inserted into the opening from within the lcrank arm and to be held therein by the resilient member acting against the inner walls of the crank arm. Thus I have provided a simple compact and light-weight construction for the crankI arm assembly and and one which permits the parts to be readily assembled. To

do so it is only necessary to insert the crank arm 21 through the central opening in the intermediate ring 39 and sleeve 38, in which positions balls 59 are placed in the lower race formed by the sleeve 38 and the crank arm 21. A second set of balls 60 are then fed into the upper races formed on the ring 39 and the crank arm 2l through the openlng 56 in the crank arm, and upon insertion of the plu 57 therein are held securely in the races. rlhus the bearing balls serve to hold' the crank plate and crank arm in assembled relation.

It will be observed` the arrangement 1s such that the thrust of the pistons is transmitted directly through the outer crank plate ring 40 and the intermediate ring 39 to the thrust bearings on the outer end of the crank arm. Also, it will be seen that the bearings are of relatively small diameter so that their peripheral speeds are reduced to a minimum with a consequent lessening of wear on the parts.

As disclosed in my said copending application the crank plate 17 is held against rotation during its wabbling movement as the crank arm 21 rotates in a conical path. Ro-

tation of the plate 17 is prevented by a geared` relationship between the ring gear 42. on the intermediate ring 39 and a bevel gear 61 formed on one end of the sleeve 36 nonrotatably held in the cylinder block 14.

As above indicated, the shaft 35 is formed integrally with the crank arm 21 and extends rearwardly through the cylinder block 14. The outer end thereof is formed to dprovide an axially` projecting substantially iametrical -rib 62 (Figs. 7 and 8) which is arranged to engage a suitable'kerf 63 in the end of the rotary sleeve member of the valve mechamsm.

It is apparent that I have produced an improved construction of aI pressure fluid. motor in which vthe parts are compactly arranged and maybe economically manufactured and easily assembled, disassembled or replaced; wherein excess weight has been lessened by the improved construction 'of certain parts and the elimination of others; and wherein the vibration and noise caused by the slapping, knocking and pounding of the piston and its associated parts/during and at the end of the exhaust stroke has been entirely overcome by the cushioning effect provided by the valve sleeve, thereby producing a corresponding increase in the efficiency of the motor.

- I claim as my invention:

1. In a device of the character described, the combination ofva rotatable shaft, an arm on said shaft disposed angularly relative thereto, and means'for imparting rotation to said shaft including a plurality of motor units arranged to operate successively, a crank plate'rotatably mounted on said arm and operatively connected with said motor units, said plate having a central opening therein adapted to receive said arm, and bearing elements interposed between the arm and the plate at spaced points along the arm, said arm having an opening therein extending radially into one of said spaced points to permit the insertion and removal of certain of said bearing elements.

2. In a device of the character described having agyrating series of bell4 cranks, a shaft having two ends alined and an intermediate section offset at an angle theretoand adapted to describe a cone in the rotation of the shaft, av sleeve-like structure about said sectionconstituting an arm common to each of the bell cranks of the series,said section being shaped to form spaced ball races, said sleeve structure providing spaced ball races complementary to the races in said section, and bearing balls for the two sets of complementaryl races, said shaft section having a passage way extending radially thereof into one of said races to permit the insertion and removal of said balls therefrom.

3. In a device of the character described having a gyrating series of bell cranks, the combination of a shaft having a hollow crank arm rigid therewith and disposed at an angle and bearing balls interposed between thel 'crank arm and the respective sections of the crank plate at spaced points along the crank` arm, said crank arm having a port providing communication with one of said bearings 'from within sald arm to permit the lnsertion y and removal of certain of said balls.

4. In a device of the character described having a gyrating seriesof bell cranks, the combination of a shaft having a crank arm rigid therewith and disposed at an angle thereto so as to describe a cone in the rotation of the shaft, a crank plate capable of rotation about said crank arm and providing an arm common to each of the bell cranks of the series, and bearing balls interposed between the crank arm and the crank plate at spaced points along the crank arm, said crank arm having a passage way therein extending radially of the axis of one of said spaced bearing points through which certain of said balls may be inserted and removed, and means for closing said passage-way.

5. In a device of the character described having a gyrating series of bellcranks, the combination of a shaft having a crank arm rigid therewith and disposed at an angle thereto so as to describe a cone in the rotation of the shaft, a crank plate capable of rotation about said crank arm and providing an arm common to each ofthe bell cranks of the series, and bearing balls interposed between the crank arm and the crank plate at spaced points along the crank arm, said crank arm having an axial bore and a radial bore at one of said spaced bearing points to permit the insertion and removal .of -certain of said balls through said arm.

6. In a device of the character described, an arm rotating upon an axis and a gyrating lnonrotating structure on said arm, two bearings arranged in spaced relation longitudinally of the arm and interposed between it and said structure, one of said bearings including a series of rolling elements coacting to hold the structure against axial movement relative to the arm, and said arm having a passa ge-way extending in part axially of said arm and communicating with one of said bearings to permit insertion and removal of said bearing elements.

7. In a device of the character described, an arm rotating upon an axis and a Wabbling non-rotating structure on said arm, bearing means interposed -between said structure and said arm and including a series of rolling elements coacting to hold the structure and arm ,against relative axial movement,'one of said parts having an opening extending substantially perpendicularly to the axis thereof through which -said elements may` be inserted or removed, and means for closing said open-ing.

` 8. In a device `of the class described having an arm rotating in a conical` path, a wabbling non-rotating plate on said arm, said plate having two ballraces facing away from each other, said arm having two ball races facing each other and having an 4opening therethrough extending' in part substantially on the axis of said arm and registering with one of said races whereby the balls for that bearing may be inserted through said opening thereinto, and removable means for closing said opening.

9. A Huid pressure operating device of the character described having, in combination, a gyrating tubular arm rotating about an axis, a pressure plate held thereon against rotation about said axis, a ball race on said arm and said plate faced to receive balls for a ball bearing therebetween, said arm having an opening therein registering with the ball race thereon whereby the balls may be inserted between said races, and

means for closing said opening lfrom the inside of said arm.

10. A device of the character described having, in combination, an arm rotating ss i about an axis, a non-rotating pressure plate mounted on said arm, complementary ball races on said arm and said plate, said arm having an opening therein permitting access to said races through said arm whereby balls. may be inserted between said races while said plate and arm are in' operative relation, andr means resili-entlyv held in said opening to prevent the escape of balls there-l through.

I1. A device of the character described having, in combination, a gyratory crank arm having thereon a pair of outwardly facing ball races, a shaft integral therewith and extending therefrom at an angle, a non-rotatable sleeve in which said shaft is arranged to rotate, a gear on one end of said sleeve, a crank plate about said crank'arm, said plate includinga ring having a gear thereon adapted to mesh with said gear on said sleeve to hold said plate against rotation, an inner sleeve about said crank arm rigid with said ring, and a pair of ball races one on sald 1nner sleeve, and one on said ring, each arranged to complement one of the ball races on said crank arm.

12. A pressure fluid actuated tool comprising a casing, a plurality of motor units arranged in circular series in the casing, a shaft having an inclined part disposed on one side of'its axis, a pressure member mounted in the casing between said part and said motor units and adapted for oscillatory movement in the operation of said units, said pressure member including an outer annular ring with one side of which said motor units are operatively connected, an inner ring fitting into said outer ring from the opposite side of the latter, a sleeve fitting into said inner ring and projecting therefrom in a direction toward said motor units, and bearings interposed between the inclined part of the shaft on the one hand and the inner ring and sleeve respectively on the other.

13. A pressure fluid actuated tool comprising a casing, a plurality of motor units arranged in circular series in the casing, a shaft mounted in the casing and having an inclined portion constituting a crank arm, a pressure member mounted 1n the casing comprising an outer ring operatively connected with the motor units, an inner ring rigid with the outer ring, a thrust bearing interposed between said inner ring and said arm, an annular member rigid with said inner ring and extending in a direction toward the motor units, another bearing inserted between said annular member and said arm, said pressure member having a gear element rigid therewith, and a stationary gear element mounted in the casing with which the gear element of the` pressure member is adapted to coact to prevent rotational movement of the pressure member.

14. In a device of the character described, the combination with a crank arm of a pair of spaced ball races, facing outwardly from the axis of the crank arm a crank plate having a three-part construction including an inner sleeve, an intermediate ring, and an outer ring all rigidly united, said sleeve and said intermediate ring being formed to provide a pair of ball races facing inwardly toward the axis of said sleeve and ring, and bearing balls entered between the inwardly and outwardly facing races.

15. A crank plate member for a motor of the character described comprising a threepart structure including a central tubular sleeve, an outer ring arranged for connection with a plurality of pistons at spaced points about the surface thereof, and a n 1ntermediate rin having seats upon 1ts inner and outer sur aces, said inner sleeves and said outer ring being constructedto be rigidly held upon said seats by a drivmg fit.

16. A pressure Huid actuated tool comprising a casing, a plurality of motor umts yarranged in circular series inthe casing, a

shaft disposed axially relative to said series of motor units and having a crank arm r1 1d therewith, and a pressure member rotata ly mounted on said crank arm and comprising a plate having in its periphery a ser1es of sockets, each of said motor units lncluding a piston having a piston rod with a bearmg ball thereon, unitary socket members carried by said balls, and means on sa1d socket members engaging said late removably to secure the sockets in sai plate.

17. A crank plate member for a motor of the character described having a plurality of hemispherical depressions therein, a plurality of unitary hemispherical cups adapted to be received in said depressions as sockets for ball and socket connections to said crank plate, and means rigidl mounted on said cups for removably securing said cups in said depressions.

18. A pressure fluid actuated tool comprising, in combination, an arm rotatable upon a fixed axis but inclined relative thereto, a wobbling non-rotating structure mounted on said arm including an annular gear element and a sleeve element secured toether in axial alinement with the inner suraces thereof in registry so as to form an elongated tubular portlon to receive said arm, said gear and sleeve elements having ball races at their opposite free ends, said arm being provided with complementary ball races, a plurality of roller elements between said races, a separately formed ring rigid with said tubular portion and extending radially outwardly therefrom, and a plurality of motor units adapted to act upon said ring to impart wobbling movement to said structure and thereby rotation4 to said arm.

19. In a pressure fluid motor, a gyrating arm having alined end portions integral therewith and rotating about a fixed axis, a three part wabbling structure capable of rotation about said arm and adapted to be slipped over one of said end portions onto said arm, said three part structure comprislng a gear element,- a sleeve intertting with said gear element to provide atubular ortion about said arm, and a ring carrie by said tubular portion extending radiallyoutwardl therefrom, said gear element and said s eeve each having a ball race thereon facing outwardly from the pivotal axis of said wabblin structure, said arm being provided with all races complementary to those races formed on said gear element and sleeve, and a plurality of roller elements between said races.

20. In a pressure Huid motor, a g rating arm and alined end portions integra therewith and rotatin about a fixed axis, a sleeve adapted to be sllpped over one of said end ortions onto sald arm, and two series of caring members interposed between said arm and sleeve at opposlte ends thereof, said arm and sleeve constituting two relatively rotatable coaxial elements, one of said elements having a passageway extending radiall of the axis of said element through whic passageway one series of said bearing members may be inserted and removed.

In testimony whereof, I have hereunto aixed my signature.

ERNEST H. SHAFF. 

